下载，安装软件包和模块

Question

当我尝试安装任何软件包或型号时，我都遇到以下错误消息

C:\Users\A492542\Downloads>pip install requests==2.21.0
Collecting requests==2.21.0
  Retrying (Retry(total=4, connect=None, read=None, redirect=None)) after connection broken by 'ConnectTimeoutError(<pip._vendor.requests.packages.urllib3.connection.VerifiedHTTPSConnection object at 0x06B24850>, 'Connection to pypi.python.org timed out. (connect timeout=15)')': /simple/requests/

请帮帮我。还可以让我知道在哪里可以下载软件包和模块吗？